Class: SyntaxTree::YARV::GetLocal

Inherits:
Instruction show all
Defined in:
lib/syntax_tree/yarv/instructions.rb

Overview

### Summary

‘getlocal` fetches the value of a local variable from a frame determined by the level and index arguments. The level is the number of frames back to look and the index is the index in the local table. It pushes the value it finds onto the stack.

### Usage

~~~ruby value = 5 tap { tap { value } } ~~~

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from Instruction

#branch_targets, #canonical, #falls_through?, #leaves?, #pops, #side_effects?

Constructor Details

#initialize(index, level) ⇒ GetLocal

Returns a new instance of GetLocal.



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1884

def initialize(index, level)
  @index = index
  @level = level
end

Instance Attribute Details

#index ⇒ Object (readonly)

Returns the value of attribute index.



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1882

def index
  @index
end

#level ⇒ Object (readonly)

Returns the value of attribute level.



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1882

def level
  @level
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1903

def ==(other)
  other.is_a?(GetLocal) && other.index == index && other.level == level
end

#call(vm) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1915

def call(vm)
  vm.push(vm.local_get(index, level))
end

#deconstruct_keys(_keys) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1899

def deconstruct_keys(_keys)
  { index: index, level: level }
end

#disasm(fmt) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1889

def disasm(fmt)
  fmt.instruction("getlocal", [fmt.local(index, explicit: level)])
end

#length ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1907

def length
  3
end

#pushes ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1911

def pushes
  1
end

#to_a(iseq) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1893

def to_a(iseq)
  current = iseq
  level.times { current = current.parent_iseq }
  [:getlocal, current.local_table.offset(index), level]
end